Electrical apparatuses are known, such as fuse holders, intended to be mounted on an attachment rail, for example within an electrical board. Such an apparatus generally comprises a bi-stable locking device, suitable for locking the electrical apparatus on the attachment rail or, alternately, unlocking the apparatus, so as to allow a movement of the apparatus relative to the attachment rail.
Typically, the known locking devices include a movable mechanical part that is attached on the casing of the apparatus. One drawback is that this involves the industrial manufacturing of the apparatus, since the mechanical part, generally made from a material different from the casing, must be manufactured separately from the casing, then next fastened on this casing.
Known from EP 2,528,178 A1 is an electrical apparatus that comprises a movable bi-stable locking device, made in a single piece with the casing of the apparatus.
This known locking device is provided with a tab that comprises, on one of its ends, a hook suitable for retaining a branch of the fastening rail and that also includes, on its opposite end, a curved maneuvering portion as well as a locking member. The locking member is arranged below the maneuvering portion and is suitable for keeping the tab in an unlocked position relative to the fastening rail. The maneuvering portion allows an operator to move the tab between the locked and unlocked positions.
This known apparatus is not, however, fully satisfactory. In particular, due to the configuration of the locking device, an operator must, in order to attach the apparatus on the attachment rail, i.e., to move the tab toward the locking position, move the maneuvering portion by pulling it toward him, i.e., toward a front face of the apparatus. Such a movement is not very intuitive, which increases the risk of incorrect maneuver and damage to the device. Such a movement is additionally inconvenient to perform when the space required for such a maneuver is insufficient, for example when the apparatus is mounted in an electrical board.
The apparatuses described in documents EP 2,264,846 A2, US 2008/186657 A1 and EP 1,775,809 A1 are also known.